Method of obtaining colored polymerized styrol and its homologues and products obtained thereby



I METHOD OBTAINING Patented Mar. 12, 1929.

UNITED STATESQ PATENT OFFICE.

OSTROMISLENSKY, Oil!" NEW YORK, N. Y., ASSIGNOR TO THE NAUGATUCK ICHEMICAL COMPANY, OF NAUGATUCK, CONNECTICUT, A CORPORATION OF CON-NECTICU T.

COLORED POLYHERIZED STYROL AND ITS HOMOLOGUES AND PRODUCTS OBTAINEDTHERE-BY.

11o Drawing. Original application. Med January 29, 1925, Serial No.5,457. Divided and this application filed March 31, 1927.

This invention relates to methods of obtaining colored polymerizedstyrol and its homologues and to the products obtained thereby.

'I Polymerized styrol may be colored by addloidal solutions in styrolglass.

properties,

ing pigment-s thereto. Such a method of coloring is limited to theformation of opaque colored masses. present invention processes havebeen developed for' preparing colored polymerized styrol which mayretain its transparent at the same time possessing fluorescence. By thepresent process it is possible to obtain an'extremely wide variety ofshades and tones far beyond thefew colors which can be obtained with theusual pigments.

With a preferred embodiment in mind and without intentionto limit theinvention be- 0nd what is required by the prior art, the inventionbriefly consists in combining with unpolymerized styrols coloring matterwhich is soluble in unpolymerized styrols and at least colloidallysoluble in the polymerized styrols. It also consists in formingpolymerized styrols from solutions of such coloring matter in liquidstyrol. The invention' also relates to methods of obtaining colors withinor anic salts, which may or ma not impart uorescence.

his ap lication is a. division, of Serial No. 5,457 ed January 29, 1925.The present application is concerned with the materials which are forthe most part inorganic, and which may be regarded as givingcolproducts, while still transparent as compared with styrol glasscolored with ordinary pigments, have the transparency Wl'llCh'lScharacteristic of colloidal solutions. They may be faintly milky butnevertheless substantially transparent; It is obvious that as the amountof coloring matter is increased, the glass may vary through the entirerange from almost water white, through transparency, translucency intoopaqueness, but for the most part styrol glass when colored withmaterials which are colloidally soluble therein will be of varyingdegrees of translucency. The ex ression styrol glass as used hereinsigni es polymerized styrol, and

According to the The colored Serial No. 180,059.

styrol without qualification signifies unpol ymerized styrol and itshomologues.

It has been discovered that a number of inorganic materials are solublein liquid styrol, that is unpolymerized styrol, and that many of thesematerials are likewise at least I makes it possible to obtain remarkableresults in purity of tint, even distribution of the coloring material,as well as in the optical and other physical properties of the glass.

Certain inorganic salts are soluble in styrol and in styrol glass. Someof these also impart colors to the glass. Solutions of colloidal metals,particularly gold, silver, and mercury can be obtained in styrol glass.Anhydrous gold chloride, silver nitrate, or hydrohalide salts of mercurycan be dissolved in styrol. When these solutions are heated to 140 180G. in the course of the polymerization of the styrols, colloidalsolutions of the metals are found simultantously. It would appear thatthe reduction of the original salts has been accomplished by the styrolitself .or by the aldehydeformed during the polymerization. It isadvisable to have a small amount of styrolglass dissolved in the styrol,to function as a protective.

colloid. 4

A small amount of gold chloride which has been dried in vacuo at 80 C.is introduce'd into styrol containing about 3-5% of styrol glass. Theresulting mixture is well shaken up and carefully heated, thetemperature being raised quite gradually to the boiling point. Theresulting, fairly opaque solution is quickly filtered ofl' through afolded paper filter while still hot and then is immediately introducedin small portions into styrol containing about 5% of styrol glass untila blue coloring somewhat deeper than the desired shade is obtained. The

shaken up and if nechours at 180 0., in the last instance .without areflux condenser. The product is styrol glass colored with colloidalgold. In

transmitted light it displays a pure light blue or deeper blue tint, andin reflected light, a soft reddish brown.

If a strong solution of gold chloride, as has already been described, isintroduced into styrol containing more than 10% of styrol glass, thecolloidal gold during the polymerization step does not have time tbecome evenly distributed throughout the glass, and the product iscolorless in some places and cloudy in others.

The color that styrol glass takes on under the action of silver nitratedepends upon the following conditions: '(1) concentration of the silvernitrate used (2) duration and temperature of the polymerization (3)purity of the silver nitrate.

Pure silver nitrate usually colors styrol glass to various shades ofbrown, or to a very dark, almost black color. When con.- taining salt tothe amount of 0.001%, glass is produced which even in a thick sheet(about 10 cm.) has a scarcely noticeable brown tint. In the presence of0.01% of sil- 1 ver nitrate the resulting glass is almost whic opaquewhen in a thick sheet, but in transmitted li ht it shows brown whilst inreflected lig t it is likewise opaque, opalescing with a dark brown,almost black color with a curious greenish reflection.

Impure silver nitrate which tarnishes when exposed to daylight or in amoist atmosphere, produces more interesting and varied colorings. Forthis purpose silver nitrate was used which had been recovered from thesilver chloride obtained from the fixin solutions used in photography.Glass contains 0.001% of such silver salts (polymerization is kept upfor- 15 hours at 140 C.) acquires a pure golden-yellow color and doesnot opalesce. When the content of silver nitrate approximates 0.013% theglass takes on a lovely dark red color, but in reflected light it showsopaque "and whitishgray of a most curious shade. In a thin sheet itdisplays a peculiar green fluor- Analogous' results were obtained with0.04% of sliver nitrate; when the content is reduced to 0.008% aninteresting reddish-brown color, without any fluorescence is obtained.

To 20 gms. of styrol containing 1+3% of styrol glass, 5 corn. of asolution of 0.02 gins. 0 silver nitrate in 50 com. of styrol whichlikewise contains 13% of styrol glass, are added, the temperature beingraised gradually. This mixture is heated with a reflux (a'ir) condenserfor 12 hours at 175 C. In the end styrol glass contain- -in to a solidstate, and recovering a polying 0.008% of silver nitrate is obtained.For co oring-glass of this kind see above. a Silver nitrate alsopossesses the property,

even when present in amounts as small as 0.001%, of rendering the styrolglass more durable, pliable and resilient.

The process is also applicable to the llght colored resins and resinousproducts, known as condensation products provided the coloring materialsare soluble in these products and are unaffected by the temperaturesreached in forming the resins. The process may also be used in coloringthe rough transparent vitreous (alpha) polymerized styrols, the beta orbrittle modification of polymerized styrol, as well as to othermodifications and to mixtures of the several modifications ofstyrolglass.

Having thus described my invention, what I claim and desire to protectby Letters Patent is: I 15 A process for producing colored polymerizedstyrols which COIIlPllSeS forming in styrol colloidal solutions ofinorganic coloring material, polymerizing the styrol there merizedstyrol containing said inorganic material in colloidal solution.

2. A process for producing colored polymerized styrols which comprisesforming a solution of an inorganic coloring compound in styrol, heatingsaid solution to polymerize the styrol into solid form, and recovering apolymerized styrol containing said inorganic material in colloidalsolution therein. 1

3. A process for producing colored olymerized styrols which comprisesdisso ving an inorganic pigmentary salt in unpolymerized styrol, heatingto polymerize the'styrol 1 into a solid form, and recovering a coloredpolymerized styrol in which the metallic radical of 'said-salt is incolloidal solution.

4. A process for. producing colored polymerized styrols which comprisesdissolving an inorganic pigmentary salt in-unpolymerized styrol in thepresence of a small amount of a polymerized styrol as a protectivecolloid, polymerizing the solution to solid form, and recovering acolored polymerized rod- .uct in which the metallic radical of saidinmerized styrol containing said metal in colloidal solution.

6. A method of coloring polymerized I styrol with metals in colloidalcondition w ich comprises forming a styrol solution of a heavy metalsalt, heating at 140-180 C. to polymerize the styrol, and recovering acolored polymerized product containing the metallic radical of said saltin colloidal solution.

7. A method of coloring polymerized styrol with metals in colloidalcondition which comprises forming a solution of a heavy metal salt inunpolymerized styrol containing a small amount of polymerized styrol asa protective colloid, heating at 140-l80 G. to polymerize the styrol,and recovering a colored polymerized product containing the metallicradical (if said salt in colloidal solution. V

8. A method of coloring polymerized styrol with metals in colloidalcondition which comprises dissolving a silver salt in unpolymerizedstyrol, heating the solution to polymerize the styrol to a solid formand recovering a polymerized product colored with said silver incolloidal solution in the mass.

9, A method of coloring polymerized styrol with metals in colloidalcondition covering a colored polymerized product containing the metallicradical of said salt in colloidal solution.

10. A method of coloring polymerized st rol with metals in colloidalcondition w 'ch comprises dissolving a silver nitrate in unpolymerizedstyrol, heating the solution to polymerize the styrol to a solid formand recovering a polymerized product colored with said silver incolloidal solution in the mass.

11. A method of coloring, polymerized styrol with metalsin colloidalcondition which comprises forming a solution of a silver nitrate inunpolymerizedstyrol containing a small amount of polymerized styrol as aprotective colloid, heating at 140 180 G. to polymerize the styrol, andrecovering a colored polymerized product containing the metallic radicalof said salt in colloidal solution,

12. As new roducts, polymerized styrols colored with heavy inorganicelements in colloidal solution.

13. As new products, polymerized styrols colored with heavy metals incolloidal solution therein.

14. As a new product, polymerized styrol colored with silver incolloidal solution therein. I

Signed at New York, county of New York $3 of New York, this 29th day ofMarch, 9 I

